1. Field of the Invention
The present invention pertains to a heater blower apparatus that is primarily intended for use as a non-dilution water heater blower. The apparatus is designed to be retrofit to an existing water heater between the axially aligned heater exhaust opening and a flue pipe.
2. Description of the Related Art
In the basic construction of a water heater, a fuel such as gas is burned in a combustion chamber of the water heater to heat water passed through the water heater. The water typically travels through a series of coils in the water heater. Combustion of the fuel in the combustion chamber produces hot combustion exhaust gas that passes through the series of coils and heats the water passing through the coils. The combustion exhaust gas then exits the water heater through an exhaust opening of the water heater and then passes through a flue pipe that conducts the gas out of the building containing the water heater.
Many prior art water heaters are connected to a flue pipe or chimney where only the draft effect of the flue pipe or chimney moves the exhaust gas up through the flue pipe or chimney. Because only the difference in temperature and pressure between the hot exhaust gas inside the water heater and the ambient air outside the water heater would cause the gas to move upwardly through the flue pipe or chimney, prior art water heaters were designed to avoid restricting the flow of the exhaust gas upwardly through the water heater to ensure that the gas would exit the water heater through the flue pipe or chimney. This limited the number of coils that could be positioned inside the water heater so as not to overly restrict the flow of the exhaust gas through the water heater. This in turn reduced the efficiency of the water heater.
To increase efficiency, water heaters have been designed where the hot gas of combustion is drawn through an increased number of coils of the water heater to provide an increased amount of heat transfer from the heat of the gas to the water passing through the coils. A greater number of coils enables a greater amount of heat transfer. However, this also required that the water heater be constructed with a blower apparatus that would draw the combustion gas through the coils of the water heater and to the flue pipe exhausting the gas.
The addition of a blower apparatus to a water heater increased the overall cost of the water heater. In addition, because the blower apparatus would draw the exhaust gas quickly through the water heater and into the blower apparatus, the increased temperature of the exhaust gas drawn into the blower apparatus often required that the blower apparatus mix ambient dilution air with the hot exhaust gas to cool the gas. The need to draw dilution air into the blower apparatus to cool the exhaust gas often required that the blower apparatus have a more complicated blower housing design and a more powerful motor for the fan of the apparatus. The more complicated blower housing design often increased the cost of manufacturing the blower apparatus, detracting from the energy savings of the dilution blower apparatus. The energy used by the more powerful motor also would negate some of the energy savings realized by increasing the heat transfer between the combustion gas and the coils of the water heater.